diff --git a/src/NHibernate.Test/Async/NHSpecificTest/GH3643/FixtureByCode.cs b/src/NHibernate.Test/Async/NHSpecificTest/GH3643/FixtureByCode.cs
new file mode 100644
index 0000000000..71b43faf92
--- /dev/null
+++ b/src/NHibernate.Test/Async/NHSpecificTest/GH3643/FixtureByCode.cs
@@ -0,0 +1,124 @@
+//------------------------------------------------------------------------------
+// <auto-generated>
+//     This code was generated by AsyncGenerator.
+//
+//     Changes to this file may cause incorrect behavior and will be lost if
+//     the code is regenerated.
+// </auto-generated>
+//------------------------------------------------------------------------------
+
+
+using System.Linq;
+using NHibernate.Cfg;
+using NHibernate.Cfg.MappingSchema;
+using NHibernate.Linq;
+using NHibernate.Mapping.ByCode;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH3643
+{
+	using System.Threading.Tasks;
+	using System.Threading;
+	[TestFixture]
+	public class FixtureByCodeAsync : TestCaseMappingByCode
+	{
+		protected override void Configure(Configuration configuration)
+		{
+			configuration.SetProperty(Environment.UseQueryCache, "true");
+			configuration.SetProperty(Environment.GenerateStatistics, "true");
+		}
+
+		protected override HbmMapping GetMappings()
+		{
+			var mapper = new ModelMapper();
+
+			mapper.Class<Entity>(
+				rc =>
+				{
+					rc.Id(x => x.Id);
+					rc.Bag(
+						x => x.Children,
+						m =>
+						{
+							m.Access(Accessor.Field);
+							m.Key(k => k.Column("EntityId"));
+							m.Cascade(Mapping.ByCode.Cascade.All);
+						},
+						r => r.OneToMany());
+			
+					rc.Cache(
+						cm =>
+						{
+							cm.Include(CacheInclude.All);
+							cm.Usage(CacheUsage.ReadWrite);
+						});
+				});
+
+			mapper.Class<ChildEntity>(
+				rc =>
+				{
+					rc.Id(x => x.Id);
+					rc.Cache(
+						cm =>
+						{
+							cm.Include(CacheInclude.All);
+							cm.Usage(CacheUsage.ReadWrite);
+						});
+				});
+
+			return mapper.CompileMappingForAllExplicitlyAddedEntities();
+		}
+
+		protected override void OnSetUp()
+		{
+			using var session = OpenSession();
+			using var transaction = session.BeginTransaction();
+
+			var entity = new Entity { Id = EntityId.Id1 };
+			entity.Children.Add(new ChildEntity { Id = 0 });
+			entity.Children.Add(new ChildEntity { Id = 1 });
+			session.Save(entity);
+
+			transaction.Commit();
+		}
+
+		protected override void OnTearDown()
+		{
+			using var session = OpenSession();
+			using var transaction = session.BeginTransaction();
+
+			session.CreateQuery("delete from ChildEntity").ExecuteUpdate();
+			session.CreateQuery("delete from System.Object").ExecuteUpdate();
+
+			transaction.Commit();
+		}
+	
+		[Test]
+		public async Task LoadsEntityWithEnumIdAndChildrenUsingQueryCacheAsync()
+		{
+			await (LoadEntityWithQueryCacheAsync()); // warm up cache
+
+			var entity = await (LoadEntityWithQueryCacheAsync());
+
+			Assert.That(entity.Children.Count(), Is.EqualTo(2));
+			
+			Assert.That(Sfi.Statistics.QueryExecutionCount, Is.EqualTo(1), "Unexpected execution count");
+			Assert.That(Sfi.Statistics.QueryCachePutCount, Is.EqualTo(1), "Unexpected cache put count");
+			Assert.That(Sfi.Statistics.QueryCacheHitCount, Is.EqualTo(1), "Unexpected cache hit count");
+		}
+		
+		private async Task<Entity> LoadEntityWithQueryCacheAsync(CancellationToken cancellationToken = default(CancellationToken))
+		{
+			using var session = OpenSession();
+			using var transaction = session.BeginTransaction();
+			var entity = (await (session
+				.Query<Entity>()
+				.FetchMany(x => x.Children)
+				.WithOptions(opt => opt.SetCacheable(true))
+				.ToListAsync(cancellationToken)))[0];
+			
+			await (transaction.CommitAsync(cancellationToken));
+			return entity;
+		}
+	}
+}
diff --git a/src/NHibernate.Test/NHSpecificTest/GH3643/Entity.cs b/src/NHibernate.Test/NHSpecificTest/GH3643/Entity.cs
new file mode 100644
index 0000000000..09f08d8dba
--- /dev/null
+++ b/src/NHibernate.Test/NHSpecificTest/GH3643/Entity.cs
@@ -0,0 +1,25 @@
+using System.Collections.Generic;
+
+// ReSharper disable CollectionNeverUpdated.Local
+// ReSharper disable UnassignedGetOnlyAutoProperty
+
+namespace NHibernate.Test.NHSpecificTest.GH3643
+{
+	class Entity
+	{
+		private readonly ICollection<ChildEntity> _children = [];
+		public virtual EntityId Id { get; set; }
+		public virtual ICollection<ChildEntity> Children => _children;
+	}
+
+	class ChildEntity
+	{
+		public virtual int Id { get; set; }
+	}
+
+	enum EntityId
+	{
+		Id1,
+		Id2
+	}
+}
diff --git a/src/NHibernate.Test/NHSpecificTest/GH3643/FixtureByCode.cs b/src/NHibernate.Test/NHSpecificTest/GH3643/FixtureByCode.cs
new file mode 100644
index 0000000000..2fc0741b48
--- /dev/null
+++ b/src/NHibernate.Test/NHSpecificTest/GH3643/FixtureByCode.cs
@@ -0,0 +1,112 @@
+using System.Linq;
+using NHibernate.Cfg;
+using NHibernate.Cfg.MappingSchema;
+using NHibernate.Linq;
+using NHibernate.Mapping.ByCode;
+using NUnit.Framework;
+
+namespace NHibernate.Test.NHSpecificTest.GH3643
+{
+	[TestFixture]
+	public class FixtureByCode : TestCaseMappingByCode
+	{
+		protected override void Configure(Configuration configuration)
+		{
+			configuration.SetProperty(Environment.UseQueryCache, "true");
+			configuration.SetProperty(Environment.GenerateStatistics, "true");
+		}
+
+		protected override HbmMapping GetMappings()
+		{
+			var mapper = new ModelMapper();
+
+			mapper.Class<Entity>(
+				rc =>
+				{
+					rc.Id(x => x.Id);
+					rc.Bag(
+						x => x.Children,
+						m =>
+						{
+							m.Access(Accessor.Field);
+							m.Key(k => k.Column("EntityId"));
+							m.Cascade(Mapping.ByCode.Cascade.All);
+						},
+						r => r.OneToMany());
+			
+					rc.Cache(
+						cm =>
+						{
+							cm.Include(CacheInclude.All);
+							cm.Usage(CacheUsage.ReadWrite);
+						});
+				});
+
+			mapper.Class<ChildEntity>(
+				rc =>
+				{
+					rc.Id(x => x.Id);
+					rc.Cache(
+						cm =>
+						{
+							cm.Include(CacheInclude.All);
+							cm.Usage(CacheUsage.ReadWrite);
+						});
+				});
+
+			return mapper.CompileMappingForAllExplicitlyAddedEntities();
+		}
+
+		protected override void OnSetUp()
+		{
+			using var session = OpenSession();
+			using var transaction = session.BeginTransaction();
+
+			var entity = new Entity { Id = EntityId.Id1 };
+			entity.Children.Add(new ChildEntity { Id = 0 });
+			entity.Children.Add(new ChildEntity { Id = 1 });
+			session.Save(entity);
+
+			transaction.Commit();
+		}
+
+		protected override void OnTearDown()
+		{
+			using var session = OpenSession();
+			using var transaction = session.BeginTransaction();
+
+			session.CreateQuery("delete from ChildEntity").ExecuteUpdate();
+			session.CreateQuery("delete from System.Object").ExecuteUpdate();
+
+			transaction.Commit();
+		}
+	
+		[Test]
+		public void LoadsEntityWithEnumIdAndChildrenUsingQueryCache()
+		{
+			LoadEntityWithQueryCache(); // warm up cache
+
+			var entity = LoadEntityWithQueryCache();
+
+			Assert.That(entity.Children.Count(), Is.EqualTo(2));
+			
+			Assert.That(Sfi.Statistics.QueryExecutionCount, Is.EqualTo(1), "Unexpected execution count");
+			Assert.That(Sfi.Statistics.QueryCachePutCount, Is.EqualTo(1), "Unexpected cache put count");
+			Assert.That(Sfi.Statistics.QueryCacheHitCount, Is.EqualTo(1), "Unexpected cache hit count");
+		}
+		
+		private Entity LoadEntityWithQueryCache()
+		{
+			using var session = OpenSession();
+			using var transaction = session.BeginTransaction();
+			var entity = session
+				.Query<Entity>()
+				.FetchMany(x => x.Children)
+				.WithOptions(opt => opt.SetCacheable(true))
+				.ToList()[0];
+			
+			transaction.Commit();
+			return entity;
+		}
+	}
+}
diff --git a/src/NHibernate/Async/Type/TypeHelper.cs b/src/NHibernate/Async/Type/TypeHelper.cs
index 3446d11524..0f04ceebb7 100644
--- a/src/NHibernate/Async/Type/TypeHelper.cs
+++ b/src/NHibernate/Async/Type/TypeHelper.cs
@@ -125,6 +125,7 @@ internal static async Task InitializeCollectionsAsync(
 					continue;
 				}
 
+				value = await (pair.Value.KeyType.AssembleAsync(value, session, null, cancellationToken)).ConfigureAwait(false);
 				var collection = session.PersistenceContext.GetCollection(new CollectionKey(pair.Value, value));
 				await (collection.ForceInitializationAsync(cancellationToken)).ConfigureAwait(false);
 				assembleRow[pair.Key] = collection;
diff --git a/src/NHibernate/Type/TypeHelper.cs b/src/NHibernate/Type/TypeHelper.cs
index 1e28e73c8a..d7278d4a38 100644
--- a/src/NHibernate/Type/TypeHelper.cs
+++ b/src/NHibernate/Type/TypeHelper.cs
@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections;
 using System.Collections.Generic;
 using NHibernate.Collection;
@@ -133,6 +133,7 @@ internal static void InitializeCollections(
 					continue;
 				}
 
+				value = pair.Value.KeyType.Assemble(value, session, null);
 				var collection = session.PersistenceContext.GetCollection(new CollectionKey(pair.Value, value));
 				collection.ForceInitialization();
 				assembleRow[pair.Key] = collection;